The principal investigator is exploring rational means for ameliorating sickle cell anemia through modifying the synthetic rates of hemoglobin-S beta chains and of non-allelic gamma chains. Minor amounts of hemoglobin F appear to suppress the vaso-occlusive episodes which are the most serious aspects of sickle cell anemia. The genetically- determined synthesis of beta and gamma chains are subject to modulation at several strategic points. The possibility of stimulating Hb-F synthesis for long periods offers reasonable hope for achieving beneficial, preventive therapy. The fundamental mechanisms of the "F- to-A switch" and of the ribosomal proteins are little understood. That mononuclear cells of man (and the highest primates) have receptors specific for binding gamma G, subclasses G1 and G3, has been defined extensively; the active segment of the Fc fragments has been broadly localized. Attempts to identify the active peptide sequence are in progress. The significance of this mechanism as regards host-defense against certain protozoan and neoplastic disorders is under study. The work of Dr. D.W. Allen on the peptide sequences of the major proteins of RNA oncoviruses is progressing rapidly. Concurrently Dr. Likhite has found recently that growing, experimental tumors in animals undergo complete rejection beginning about 2 weeks after injection of living tumor cells in the presence of certain "adjuvants". The availability in this laboratory of sequenced species-specific oncornovirus protein having inter-species homology, and the means for inducing an immunological-type of tumor rejection offers considerable promise for detecting, immunizing, and possibly eradicating certain classes of malignancy.